The field is that of medical instruments, including instruments for direct patient care at home, for laboratory use, and for clinical or hospital use in conjunction with patient care.
Patients and operators of medical machines and instruments may be under a good deal of stress, caused by health concerns and the need for using the medical instruments. These may include dialysis machines, blood separators, sample preparation machines, drug dose preparation devices, and so forth. The stress may be exacerbated by the need for close proximity to the machine for hours on end, such as an overnight peritoneal dialysis procedure. The constant noise made by such machines may be very aggravating and annoying to patients who must remain connected to the machine for hours on end. Other medical instruments that reside in close quarters with operating personnel, such as laboratory sample preparation machines with centrifuges, may also emit annoying sounds.
One way to avoid these sounds is to enclose the medical device or instrument in a separate room or enclosure. This will isolate the annoying sounds from the patient or user. However, some machines, such as blood separators or dialysis machines are better used with short runs of tubing to the patient, and separate enclosures may not be practical. Another way is to provide a separate sound system to generate masking sounds or to play music. This method, however, would require a separate sound system for each medical device, and would be both expensive and cumbersome.
Some medical instruments have artifacts by which they generate their own “masking sounds.” For example, a compressor that operates a dialysis system generates a constant hum that masks other sounds from the instrument, such as the venting of air or the clicking of valves. While the hum itself is not annoying, the hum will change pitch depending on its load and also depending on the portion of the dialysis cycle. This change in pitch, sometimes also accompanied by a change in volume, is noticeable to the patient. Other techniques in general use include efforts to reduce overall machine noise. When a particular noise is eliminated, however, other noises may then become apparent. An example is using a housing or baffles to enclose and silence the above-mentioned compressor. Once the compressor is silenced, the clicking of the valves, the creaking of the dialysis door assembly, and even the swishing of fluid within the dialysis disposable portion become relatively louder and more noticeable.
What is needed is a way to reduce or mask noise of medical instruments so that the instrument is less noticeable to a user or an operator of the instrument. The method used should not interfere with operation of the machine, should be economical, and not require any further separation of the medical instrument from the patient or user. It would also be desirable if the method could be retrofitted onto existing medical instruments.